RETRACTED: Preventing dementia through correcting hearing: huge progress but more to do
Authors: Gill Livingston, Sergi Costafreda
Journal: The Lancet Public Health (2023)

Worldwide hearing loss is a major modifiable risk factor for dementia, with the largest effect in the population.1Livingston G Huntley J Sommerlad A et al.Dementia prevention, intervention, and care: 2020 report of the Lancet Commission.Lancet. 2020; 396: 413-446Summary Full Text Full Text PDF PubMed Scopus (3218) Google Scholar A systematic review published in February, 2023, included 25 observational studies and six trials on the association of correcting hearing loss with hearing aids or cochlear implants and cognitive decline or dementia.2Yeo BSY Song HJJMD Toh EMS et al.Association of hearing aids and cochlear implants with cognitive decline and dementia: a systematic review and meta-analysis.JAMA Neurol. 2023; 80: 134-141Crossref PubMed Scopus (11) Google Scholar The review included a meta-analysis of eight cohort studies with 126 903 participants and a follow-up of 2–25 years, and found that people with hearing loss who used hearing aids had an 19% lower risk of cognitive decline and a 17% lower risk of dementia, compared with those with uncorrected hearing loss. Short-term trials showed slight cognitive improvement in those who received hearing aids. However, the authors found no long-term trials of the effects of cochlear implants on the risk of subsequent dementia. In The Lancet Public Health, Fan Jiang and colleagues3Jiang F Mishra SR Shrestha N et al.Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort.Lancet Public Health. 2023; (published online April 13.)https://doi.org/10.1016/S2468-2667(23)00048-8Summary Full Text Full Text PDF PubMed Scopus (6) Google Scholar report an analysis of longitudinal data from 437 704 individuals from the UK Biobank (235 249 (53·7%) were female, 202 455 (46·3%) were male, and 416 131 (95·1%) were White, with a mean age at baseline of 56·0 years [SD 8·0]). The analysis found a 42% increased risk of dementia in people with self-reported hearing loss compared with those without (hazard ratio 1·42 [95% CI 1·28–1·57]). However, the authors found no increased risk in those who used hearing aids. The findings from Jiang and colleagues reinforce the possibility that untreated but not treated hearing loss confers increased risk of dementia. An analogous case exists for hypertension, with consistent evidence that anti-hypertensive medication can mitigate dementia risk.4Hughes D Judge C Murphy R et al.Association of blood pressure lowering with incident dementia or cognitive impairment: a systematic review and meta-analysis.JAMA. 2020; 323: 1934-1944Crossref PubMed Scopus (182) Google Scholar, 5Peters R Beckett N Forette F et al.Incident dementia and blood pressure lowering in the hypertension in the very elderly trial cognitive function assessment (HYVET-COG): a double-blind, placebo controlled trial.Lancet Neurol. 2008; 7: 683-689Summary Full Text Full Text PDF PubMed Scopus (639) Google Scholar However, unlike for hypertension, no randomised controlled trials of hearing aids and dementia risk have been done. Observational findings might be confounded, as those who use hearing aids might have better access to financial, social, or cognitive resources to look after their health compared with those with hearing loss without hearing aids. Jiang and colleagues add extensive sensitivity and interaction analysis. Their findings did not change when restricted to those who developed dementia 10 years or more after baseline, indicating that reverse causation is an unlikely explanation of their findings. The authors also did a competing risk analysis, which showed that findings were not explained by earlier death of those using hearing aids compared with those without hearing aids. Additionally, interaction analysis indicated that cardiovascular disease has no bigger role in dementia in those with hearing loss than in those without and is therefore unlikely to confound the findings by causing both hearing loss and dementia. In line with this finding, the authors found that hearing aid use protected from all-cause dementia and dementia subtypes. This finding suggests that hearing aids might work by supporting brain resilience rather than by reducing specific forms of neuropathology. Hearing loss was self-reported in this study, so its effects were probably underestimated because many people do not realise that they have hearing loss. All participants in the study were UK Biobank volunteers who, on average, have better health and are more likely to be from higher socioeconomic strata than the general population. Despite this demographic sample, and hearing aids being free of charge in the UK National Health Service, most people with hearing loss did not use hearing aids in this study (98 730 [88%] of 111 822 participants). Hearing loss is often under-recognised and under-treated. Hearing aid use requires awareness of hearing loss and access to the technology, but also perseverance, manual dexterity, and maintenance, and hearing aid use can be stigmatising and considered unappealing. With the addition of Jiang and colleagues' work,3Jiang F Mishra SR Shrestha N et al.Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort.Lancet Public Health. 2023; (published online April 13.)https://doi.org/10.1016/S2468-2667(23)00048-8Summary Full Text Full Text PDF PubMed Scopus (6) Google Scholar the evidence that hearing aids can be a powerful tool to reduce the risk of dementia in people with hearing loss is as good as possible without randomised controlled trials, which might not be practically possible or ethical because people with hearing loss should not be stopped from using effective treatments. Dementia is not only an illness that affects the individual and their family, but it can also be expensive. However, using hearing aids to prevent dementia has been found to be cost-effective and cost saving.6Mukadam N Anderson R Knapp M et al.Effective interventions for potentially modifiable risk factors for late-onset dementia: a costs and cost-effectiveness modelling study.Lancet Healthy Longev. 2020; 1: e13-e20Summary Full Text Full Text PDF PubMed Scopus (22) Google Scholar In the USA, hearing aids have become available to purchase over the counter, thus making them more accessible.7Lin FR Reed NS Over-the-counter hearing aids: How we got here and necessary next steps.J Am Geriatr Soc. 2022; 70: 1954-1956Crossref PubMed Scopus (1) Google Scholar The evidence is compelling that treating hearing loss is a promising way of reducing dementia risk. This is the time to increase awareness of and detection of hearing loss, as well as the acceptability and usability of hearing aids. We declare no competing interests. Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohortIn people with hearing loss, hearing aid use is associated with a risk of dementia of a similar level to that of people without hearing loss. With the postulation that up to 8% of dementia cases could be prevented with proper hearing loss management, our findings highlight the urgent need to take measures to address hearing loss to improve cognitive decline. Full-Text PDF Open AccessAddressing hearing loss at all agesMore than 1·5 billion people experience some degree of hearing loss, a number that could increase to 2·5 billion by 2050, according to WHO's World Report on Hearing . Hearing loss is often seen as an invisible disability. Not only because it is not associated with visible signs but also because it does not receive the attention it should. The consequences of hearing loss can be profound. Untreated hearing loss can be associated with unemployment, social isolation, and affect quality of life. In children, hearing loss can affect spoken language and development. Full-Text PDF Open Access